This study is concerned with characterizing the processes associated with regulating calcium levels in the nervous system. Toward that end, experiments to measure efflux and influx of calcium at isolated nerve endings and at isolated sympathetic ganglia are planned. In addition, properties of a Ca-stimulated ATPase in membrane fractions of brain are to be studied. BIBLIOGRAPHIC REFERENCES: Goddard, G. A. and Robinson, J. D.: Uptake and release of calcium by rat brain synaptosomes. Brain Research 110, 331-350 (1976). Robinson, J. D.: (Ca plus Mg) - stimulated ATPase activity of a rat brain microsomal preparation. Arch Biochem. Biophys. 176, 366-374 (1976).